when you say "pure", I assume you're contrasting the situation where a
population is defined by long-term *in situ* adaptation and some
degree of breeding isolation from surrounding poulations, as oppossed
to hybridization between two or more such pre-existing groups. I
haven't seen convincing evidence one way or the other, though I lean
towards the former. It appear to be the more parsimonious explanation.

|> geroldf@sdd.hp.com (Gerold Firl) wrote:|> >For the japanese, we have the ainu, east asians, and okinawan-type|> >aborigines as their progenitors; who would you suggest for the|> >indo-europeans?

|> Well, lets see. There are those who argue that hamito-semitic and|> indoeuropean languages are related, and given the fact that these|> cultures were located at apposing ends of the black sea and|> overwhelming likelyhood of gene transfer in that region.

Actually, there are significant geographical barriers between the
homelands of the IE and HS populations. The black sea, the caspian,
and the highlands of anatolia, the caucasus, and iran would provide
suffient isolation to inhibit genetic transfer; in addition, the two
areas are subject to very different kinds of selection pressures.
Linguistic affinity between HS and IE languages is an interesting
connection, but I have a hard time relating it to the evolution of
either language or populations. Any suggestions?

In addition|> if you are going to consider this one must also consider the|> paleo-anatolians and the peoples of the balkans who have had|> reasonalby advanced and seafaring cultures during the immediate|> prehistoric period. Then to add to this, one has the stem populations|> of asian groups such as the ural/altaic peoples and other minor asian|> groups in the region. To the west there are possible influences of the|> neo-lithic groups which the indoeuropeans eventually conquered. Little|> if anything is known about these peoples however, this does rule out|> some previous genetic contribution.

People move, genes move, but local variation in selection criteria
plus geographic barriers will maintain steps in the cline. Those steps
are the logical place to differentiate subpopulations, and all the
groups you list above precisely match the conditions for existing as a
distinct subpopulation.

My best guess is that the proto-IE people occupied the great swath of
steppe lands from the ukraine east to lake balkash, descending
directly from the ice-age big game hunters whose mammoth-tusk shelters
are so well known. They probably had pretty close affinity to the more
westerly europeans as well; the hungarian and north german plains are
similar habitats.

The sheer size of this ecosystem creates some interesting dynamics for
hunter-gather residents. Some of the modern characteristics of IE
societies may still be tracable to those conditions.

One has to consider that prior to|> 12 KYA that this group may have been a part of some larger regional|> group which split off as the glaciers in the region retreated.

What did you have in mind? I think the eurasian steppe remained as a
single ecumene throughout the transition to this interglacial.

|> Part II the sorting of Sub Saharan Africans|> |> >|> I personally don't think that there is any|> >|> firm genetic foundation at yet, and until such a foundation is|> >|> provided I would pretty much leave the cataogorization of SSA types|> >|> alone

|> >Is it politically sensitive? There seems to be ample historical and|> >archeological evidence to reconstruct the big-picture taxonomy.

|> Not at all, its kind of the once shot twice shy hesitation. historic|> and estimated recent prehistoric events are fine, but the fact is that|> this represents a small temporal part of the larger 'history' of human|> africa in which the genetic studies haven't even began to touch upon.|> Given the historic misassessment of the origins other populations in|> the world I think that these types of speculations are best reserved|> until after more foundational genetic information is provided. Having|> said this, I think that in some form you are likely to be correct;|> however, the evalutaion i mentioned above is not going to be easy.

Hmm, the 5-fold division into bushmen, pygmy, negro, nilo-sudanese,
and abyssinian looks pretty clear-cut to me; for the purpose of
taxonomic consistancy with a distinction such as
ural-altaic/dravidian/indo-european it may be necessary to further
subdivide the subsaharan races, but it's a good start.

|> OTOH, other regions are going to be cyclically affected by climactic|> changes resulting indirectly from the glaciation cycles. Since the|> climate changes will affect carrying capacity cyclical overpopulation|> will result in probable force migrations, hightened disease|> transmission, etc. and its likely that the regional distribution of|> peoples will change.

Right. This is a key factor which is often overlooked in studies of
human evolution. Glacial/interglacial cycles have followed one another
during the last few million years of human evolution with a
periodicity of abouut 100,000 years. Since h. erectus left africa
about 1 million years ago, the old world hominid population has gone
through about 10 cycles of glaciation. Moving to greener pastures has
a long history for humans, and one of the aspects of culture which I
consider to be of supreme importance is _making a virtue of
necessity_. Go west, young man.

|> inhabitiants. I think its safe to say that given the vast amount of|> gradient populations right now, that most populations are in fact the|> result of gradient type mixing and few residual extremes exist. If one|> wants to define races as the extremes I might point to three or four|> (that I can think of)|> |> 1. the tribes of south america|> 2. the aboriginal peoples of australia, and some pacific islands|> 3. african bushmen/pygmies.

Don't lump the pygmies and bushmen together; they are very distinct
peoples. The pygmies are adapted to the rain forest environment,
whereas the bushmen lived in more open country. The genetic distance
between them might be greater than that between swede and han.

|> >during an interglacial, the sahara is an extremely effective genetic|> >barrier. More effective than the alps, maybe even more than the|> >himalayas. During glacial periods, however, the sahara becomes very|> >hospitable savanna, opening the barrier and allowing relatively easy|> >gene flow.

|> The problem is that as a barrier it takes 2 or three thosand years|> post deglaciation and probably the advent of domesitcated animals to|> create what we see today, and as a barrier there are other problems|> (see below)

Actually, domesticated animals are not necessary to create the desert.
They can enlarge it, but the cycle of desert/savanna continues
regardless. Look at it from the standpoint of a 100,000 year cycle; a
lag of a few thousand years is insignificant.

See william calvin's web page for a wonderful selection of readings
on human evolution, particularly on the sahara pump.